1. Field of the Invention
The present invention relates to outdoor and patio umbrellas, and in particular, to a spring and stretcher system for use with outdoor and patio umbrellas.
2. Description of the Prior Art
Outdoor and patio umbrellas (hereinafter referred to collectively as patio umbrellas) have become increasingly popular, due to newly found uses and applications. Patio umbrellas have traditionally provided shade from sunlight in patios, backyards, swimming pools and other play or recreation facilities.
Recently, hotels, resorts, and restaurants have also taken advantage of the shade protection of these umbrellas for their guests and have become major purchasers. In particular, patio umbrellas will usually see extended usage in tropical countries and other warm weather resort areas.
In order to be used outdoors safely, patio umbrellas must carry enough weight to provide the necessary stability against the elements. However, most patio umbrellas are typically heavy, bulky, and large in size, which makes them somewhat inconvenient to store and transport.
In order to be used outdoors, patio umbrellas must be durable, safe, and easy to use. Many patio umbrellas employ a pulley and cord to open and to close the umbrella. However, because the cord rubs and chafes against the pulley, the fibers of the cord eventually fray and disintegrate. In addition, with this wear and tear, even the pulley mechanisms have a tendency to wear out from the constant rubbing of the metal parts and from the force applied from the pulling of the cord. Thus, after extended normal use, both the pulley and rope mechanisms may become defective or break.
Given their size and weight, breakage of any part of the umbrella may compromise the stability of the entire umbrella structure. Any breakage could also possibly lead to the dangerous collapse of the umbrella upon those people who are positioned under the umbrella.
Even if the breakage does not compromise the stability and safety, it can still be troublesome and expensive to either (1) repair the umbrella, or (2) replace the pulley system, or (3) dispose of or replace the old umbrella with a new one, especially if the repair and replacement is required on a regular basis.
In addition, having to pull a cord to open and close a large and bulky patio umbrella is inconvenient and time consuming. More importantly, this task requires the exertion of a large amount of force, which is something that certain people (e.g., young children, some women, and some senior citizens) will have find great difficulty in doing. To these people, this exertion of force can even pose health dangers.
Thus, there remains a need to provide a patio umbrella that has increased durability, maximizes safety, and is easy to use.
It is an object of the present invention to provide a patio umbrella that is convenient to open and to close.
It is another object of the present invention to provide a patio umbrella that minimizes the possibility of breakage of any of its components.
It is yet another object of the present invention to provide a patio umbrella that does not require the use of a cord and pulley system.
To accomplish the objects of this invention, there is provided a patio umbrella having a pole, a plurality of primary ribs extending from the pole, a hub slidably supported on the pole, and a plurality of secondary ribs, each secondary rib having a first end pivotally coupled to the hub and a second end pivotally coupled to one of the primary ribs. The patio umbrella has a ledge positioned on the pole, and a spring slidably supported on the pole between the hub and the ledge. When one of the primary ribs of the umbrella is lifted, the spring will bias the umbrella into an opened position. The umbrella can be closed by compressing the spring, and maintained in the closed position by restraining the spring in its compressed position.
In one embodiment of the present invention, the patio umbrella has at least one stretcher having a first end pivotally coupled to one of the secondary ribs, and a second end pivotally coupled to the ledge.
In another embodiment of the present invention, the patio umbrella further includes covers for the spring.